Pub. date: 2006 | Online Pub. Date: September 15, 2007 | DOI: 10.4135/9781412939584 | Print ISBN: 9780761930877 | Online ISBN: 9781412939584| Publisher:SAGE Publications, Inc.About this encyclopedia
A variable may be defined as a concept or a characteristic that involves variations. Researchers use variable rather than concept or characteristic because most of what is studied varies, that is, involves variation that can be described numerically or categorically. Variables are composed of attributes or levels. An attribute is the value or category that makes up the variation. Thus, for example, the variable gender would have as attributes female and male . These categories may also be referred to as levels. A precise definition of each variable communicates clearly the researcher's intent and enhances the usefulness of the results. Two types of definition of variables are commonly used in research: conceptual and operational. A conceptual definition uses other words and concepts to describe the variable, as in a dictionary. Conceptual definition is important in ...